Numerical Simulation Of Partial Hardening And Experimental Research On HSS Hot Stamping

Recently,as the car sales increased gradually, people pay more and moreattention to the safety performance and the environmental protection.In order toensure the safety of the car,lower body quality could save energy, reduce emissions,improve the environmental protection.HSS plate hot stamping technology isdescribed to transform the austenitizing sheet in stamping process on the fastcooling,and Martensite structure is obtained.So the HSS get a greater number ofstrength and hardness.HSS plate can be used in car body meet the security under thepremise of lower the quality of parts,energy savingeffect is achieved.Differentcomponents require their different position strength.For such components can beachieved by partial hardening technology.By adjusting the cooling speed of mould atdifferent positions of HSS parts to achieve partial hardening.In this paper, the research is focused on the water flow rate and the holding timein the process of HSS hot stamping technology. Through the method of numericalsimulation and experiment contrast, analysising the relationship between the holdingtime and the water flow rate. Analyzed The influence of the holding time and thewater flow rate for partial hardening technology. Get the following conclusion:(1) The martensitic transformation curve shows that if you want to get HSS, theholding time must be within10s. In order to speed up the production cycle andimprove the efficiency of the enterprise, the holding time of the u-shaped partsforming process were analyzed. Got the best holding time for5s. When in the HSShot stamping, the holding time should be minimum of5s, no more than10s.(2) The martensitic transformation curve shows that if you want to get HSS,need to keep certain cooling speed to achieve the transformation of austenite tomartensite. According to the actual production, parts under a certain water flow rateto keep up the cooling speed satisfies the requirement of parts organizationtransformation. Through the numerical simulation analysis we can know when waterflow speed greater then0.3m/s, u-shaped parts meet the requirements of the organization transformation.(3) There are inseparable relationship between the holding time and the waterflow rate in partial hardening technology. We can increase the holding time or waterflow rate to achieve partial hardening technology. Both have their own advantages.Increasing the holding time can reduce the water flow speed. It can reduce therequirement of equipment, and reduce the production cost; Increasing the water flowspeed can reduce the holding time. It can reduce the production cycle, and improveproductivity.(4) Comparing with the results of The u-shaped parts hot stamping and thesimulation analysis. We can know that simulation results match well with theexperimental results when water flow rate are0.3m/s and1.0m/s. Due to theconstraints such as experimental environment and the handling time, lead tosimulation results unmatch well with the experimental results when water flow rateare0.1m/s. But the experimental results overall trend consistent with the simulationresults.